.iv THE <;ru,s AND TERNS. 221 



Only two species of AV.v.sw are known, both of which belong to 

 North American fauna. They may readily be distinguished 

 by the following characters: 



1. E. tridactyla. Legs and fe t black; wing, about 12.25 inches; en'iinen, 1.10-1.50; 



depth of bill at base. ..v.); tarsus. 1.30; middle toe with claw. 1.80. 



2. E. breviro3tris. Legs and feet deop coral- or vermilion-red (drying yellowish); 



wing, about 13.00 inches; cidmen, 1.20; depth of bill through base, 50; tarsus, 1.25; 

 middle toe with claw, nearly 2.00. HAS. North Pacific, particularly the American 

 side. 



Rissa tridactyla (Linn.) 



KITTIWAKE. 



Popular synonyms. Kittiwake Gull; Tarrock (England, name for young); Winter Gull, 

 Pinyole, or Pinny Owl (Newfoundland Banks). 



Larus tridactylus LINN. S. N. ed. 10, i, 1758. 136; ed. 12, i, 1766. 224. Sw. & RICH. F. B.-A. ii, 1831, 

 423. NUTT. Man. ii, 1834, 298 AUD. Orn. Biog. iii, 1835, 186. pi. 224; Synop. 1839, 

 32G; B. Am. vii, 1844, 146 pi. 444. COUES. Key, 1872. 314; Check List, 1873, No. 552. 

 K/xsa tridactyla BONAP. Comp. List, 1838, C2. LAWK, in Baird's B. N. Am. 1858, 854. 

 BAIED, Cat. N. Am. B. 1859, No. 672. SAUNDEKS, P. Z. S. 1878, 103 (synonymy, et .). 

 EIDG-W. Nom. N. Am. B. 1881, No. 658; Man. N. Am. B. 1887, 25. COUES, 2d Check 

 List, 1882, No. 782. A. O. U. Check List, 1886, No. 40. 

 liissa tridactyla, a. tridactyla B. B. & E. Water B. N. Am. ii, 1884, 202. 

 Larus (Rissa) tridactylus COUES, B. N. W. 1874, 644. 



Larus rinsa BBUNN. Orn. Bor. 1764, 42 LINN. S. N. ed. IL>, i, 1766, 224. 



Larus albus MULLEB, Natursyst. 1776, 108 (based Buffon's Monette cendree tachettet>1. 



Larus cinerarius FABE. Fauna Groenl. 1780, 101 (not of LINN. 1766. Winter plum;ige). 



Larus ncevius SCHAFF. Mus. Orn. 1789, 64 (not of LINN.). 



Larus torquatvs PALL. Zoog. Itosso-As. ii, 1826. 328. 



Larus canus PALL. 1. c. 330 (not of LINN.). 



Larus gavia, PALL. 1. c. 329. 



Larus riga GMEL. S. N. i, pt. ii, 1788, 594 (misprint). 



Rissa brunnichii LEACH, Stephen's Gen. Zool. xiii, pt. i, 1826, 181, pi. 21. 



Rissa cinerea EYTON, Cat. Br. B. 1836, 52. 



Laroides minor BEEHM, Vog. Deutschl. 1831, 756. 



Rissa b realis BEEHM, Naum. 1855, 294 (not Larus borealis BBUCHJ. 



Rissa gregaria BEEHM, 1. c. 



HAB. Circumpolar regions in summer, coming south in winter to the Middle States 

 and Great Lakes. 



SP. CHAE. Adult in. summer: Mantle deep pearl-gray (about the same shade as Larus 

 brachyrhynchus and L. califomicus). the secondaries passing into white terminally. Pri- 

 maries paler pearl-gray, the five outer quills with their terminal portion black, this color 

 extending for about 3. 25 inches on the outer and .75 of an inch, more or less, on the fifth, and 

 of intermediate extent on those between; outer web of the exterior quill almost wholly- 

 black; inner quills pale pearl-blue, scarcely paler terminally, the sixth sometimes marked 

 with a black spot near the end of the outer web; fifth quill tipped with white, and fourth 

 with a minute apical spot (when not worn off). Rest of the plumage snow-white. Bill pale 

 ypllow, sometimes tinged with greenish; inside of mouth vermilion-red: eyelids red; iris 

 brown; legs and feet black or dusky brown. .1 >///, in winter: Similar, but nape and ocvi- 

 put washed with the color of the back, the auricular region, and immediately in front of the 

 eye, with a dark plumbeous suffusion, sometimes extending across the occiput. Young, 



